AI Model Release Tracker - Timeline of Major AI Models from 2022-2026

Claude 2.1 vs o1-pro

Anthropic
Claude 2.1
OpenAI
o1-pro
Overview
CompanyAnthropicOpenAI
Release dateNov 21 2023Mar 19 2025
AccessProprietaryProprietary
Timeline
Release gapClaude 2.1 shipped 484 days before o1-pro

Which is better: Claude 2.1 or o1-pro?

Claude 2.1 and o1-pro don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Claude 2.1 shipped 484 days before o1-pro, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

Direct benchmark comparisons are unavailable — Claude 2.1 and o1-pro don't publish scores on any of the same benchmarks.

Frequently asked questions

Claude 2.1 was released by Anthropic on Nov 21 2023.

o1-pro was released by OpenAI on Mar 19 2025.

Other comparisons